I used to have a button quail who got live mealworms. I fed her gamebird feed as her base diet, but that isn't quite enough protein for them. I limited her to 5-8 mealworms a day, depending on size, because of the fat, but she loved them. She wasn't a very friendly bird, but she would just come running for a mealworm. I gave her live mealworms, since that way I could be sure they were eating a decent diet before she ate them (they got mostly Cheeky's leftover pellets, oatmeal, cereal, and some carrot slices for water). She would just gulp them down whole.
One time, Cheeky GCC was curious about the mealworms, so I let her try one. It was not pleasant (she wanted to eat it slowly, wiping mealworm guts off her beak after each bite). So no more live mealworms for her. But for button quail, they are practically necessary to give them enough protein.